Psychosocial oral health‐related quality of life impact: A systematic review

Abstract Background Psychosocial wellbeing is an important determinant for patients' oral health‐related quality of life (OHRQoL). Psychosocial impact (PI), together with the dimensions Oral Function, Orofacial Pain and Orofacial Appearance, has been proposed to cover the different areas of OHRQoL. Objective The objective of the study was to collect further scientific support for the new four‐dimensional structure of OHRQoL. This study is one out of a series of four and focuses on the PI in patients with dental anxiety, oral cancer and periodontitis (PROSPERO registration number: CRD42017064033). Methods Five databases (Pubmed (Medline), EMBASE, Cochrane, CINAHL and PsycINFO) were electronically searched on 8 June 2017 and updated on 14 January 2019, to identify the studies that measure OHRQoL using the Oral Health Impact Profile (OHIP) for oral health conditions. In this review, studies were included if the mean/median domain scores from OHIP‐14 or OHIP‐49 were available for patients with dental anxiety, oral cancer or periodontitis. The score of the handicap domain from the OHIP was used to assess patients` PI. The handicap domain includes 6 items for OHIP‐49 with a domain score ranging from 0 to 24 and 2 items for OHIP‐14 with a domain score ranging from 0 to 8. For comparison between the 2 versions of the OHIP, the domain score of OHIP‐49 was conversed into a 0 to 8 metric. The domain scores of the included studies were then pooled, separately for each of the included dental disorders. Results A total of 2104 records were identified based on the search strategy. After screening of titles and abstracts, 1607 articles were reviewed in full text. Twenty‐three articles met the inclusion criteria for this review and were included in the study. The 23 articles contained 3884 patients, grouped in 30 patient populations and 42 patient samples. The pooled mean scores of PI for dental anxiety, oral cancer and periodontitis were 3.2, 1.9 and 0.8, respectively, on the 0 to 8 metric. Conclusion This review provides standardised information about the OHRQoL impact for three dental disorders as a model for the PI dimension. Dental anxiety tends to show the strongest effect on the PI dimension, while periodontitis tends to show the weakest effect on the PI dimension. Future studies need to confirm whether the reported differences in PI scores between the three dental disorders are statistically significant.


| INTRODUC TI ON
In daily practice, a dentist needs to objectify a patient's complaints both on a physical level and on a psychosomatic level. Based on this information, a patient-tailored treatment plan can be developed, taking into account patient characteristics that may interfere with healing and/or treatment adherence. 1 Clinicians in most (if not all) medical fields accept the biopsychosocial model as the most heuristic approach to understand and manage (chronic) pain and dysfunction. In this model, pain and disability interact with psychological and social factors, and these factors together determine the impact of a clinical condition on the individual patient. 2 In the field of dentistry, this dual-axis approach is incorporated in the diagnostic classification for temporomandibular disorder patients 3 and could be applied to other pain conditions, including the various dental pain patients. 1 Options to measure psychological and social factors include questionnaires on specific constructs, like depression, 4 anxiety 5 or social support. 6 During the treatment process, the outcomes of treatment are continuously monitored and compared with the expectations for that treatment. Patient-perceived impact of treatment nowadays is considered a highly important tool to evaluate treatment success. To measure the patient-perceived impact consistently across different oral health conditions, the concept of Oral Health-Related Quality of Life (OHRQoL) is widely acknowledged. The most commonly used questionnaire to measure OHRQoL is the Oral Health Impact Profile (OHIP). 7 The OHIP was originally developed and evaluated by Slade and Spencer in 1994. 7 Up to date, the OHIP has been translated into multiple languages and is further developed into several versions with a smaller number of items as compared to the original 49-item of the OHIP, such as the 14item version. 7,8 In both OHIP-14 and OHIP-49, seven domains of OHRQoL are incorporated, covering functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability and handicap. The OHIP can be used to capture changes in health, with a proposed 7-day recall period. 9 In clinical practice and research, both OHIP-14 and OHIP-49 are widely used for the assessment of OHRQoL in different target populations. However, OHIP-14 is preferred to OHIP-49 by researchers and clinicians because it is more practical due to less number of items, while it still has acceptable reliability, validity and precision. 8 Recent empirical data have shown that an approach using only four dimensions (ie Orofacial Pain, Orofacial Appearance, Oral Function and Psychosocial Impact) can serve as a more simple and clinically appealing set of OHRQoL dimensions and still provide a psychometrical accurate OHRQoL measurement. 10 In a recent systematic review, it was found that the four OHRQoL dimensions were the attributes that underlie all generic dental patient-reported outcome measures. 11 In this special issue, the utility of the four-dimensional structure of OHRQoL is evaluated. 10 In a series of four systematic reviews, one for each dimension, further evidence for the concept of these new dimensions is sought. Therefore, the aim of this systematic review is to collect further scientific support for the new four-dimensional structure by specifically describing the psychosocial impact (PI) on OHRQoL in dental patients. For this purpose, dental patient populations with presumed elevated levels of PI, as well as dental patient populations with more equally distributed impacts on the four dimensions, were included in the review (ie patients with dental anxiety, oral cancer and periodontitis).

| MATERIAL S AND ME THODS
The protocol that was used in this systematic review was registered in PROSPERO (CRD42017064033) and was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

| Subjects and outcome variable of the study
The target populations selected for this review were patients with dental anxiety, oral cancer or periodontitis. These patient groups were selected, because patients with dental anxiety were assumed to be mostly affected on the psychosocial aspect of OHRQoL, relative to the other dimensions, while patients with oral cancer and patients with periodontitis were assumed to be more equally affected on the four dimensions. 12 To assess the PI of the patient group, both publications using the OHIP-49 7 and the OHIP-14 8 questionnaire were used. As proposed in the four-dimensional structure for the description of OHRQoL, the handicap domain from the OHIP was used to assess patients' reported differences in PI scores between the three dental disorders are statistically significant.

K E Y W O R D S
dental anxiety, oral cancer, Oral Health-Related Quality of Life, periodontitis, psychosocial impact PI in the present study. 12 In other words, the two items from the handicap domain of OHIP-14 or the six items from the same domain of OHIP-49 were used to assess the PI dimension.

| Literature search
A review of the literature was conducted by a trained librarian (NTM, see Acknowledgements) who utilised natural language to identify all articles that measure OHRQoL, for any oral health condition, using the OHIP. The keywords used to retrieve the articles were 'Oral Health Impact Profile' or 'OHIP'. The searches were per-

| Data extraction
For all included studies, the following data were extracted using a For included articles which had more than one patient sample, the characteristics of patients in each sample were extracted separately.

| Quality assessment
The methodological quality of included studies was assessed based on a 10-item appraisal tool for prevalence studies. 14 The risk of bias was assessed separately for each patient sample of the included studies.
Six of the 10 items were deemed useful for the risk of bias assessment of the included studies, that is representativeness of the samples, recruitment, characterisation of the subjects and the settings, coverage of the samples in the data analysis, standard criteria for measurement of the conditions and reliability of measurement of the conditions. The answer to each question is 'Yes', 'No' or 'Unclear'. A 'risk of bias' judgment ('low', 'unclear' or 'high') was made for each signalling question. If the answer to a signalling question was judged as 'Yes', it was judged as 'low risk' of bias for this question. If the answer to a signalling question was judged as 'No', it was judged as 'high risk' of bias for this question. Otherwise, the question was judged as 'unclear risk'.
For more detail on quality assessment, see the methods chapter. 12 The quality assessment was performed independently by three authors (NS, CV and AvW), and consensus was reached through discussion.

| Data synthesis and analysis
To enhance comparison of data between papers that used different versions of the OHIP, mean domain scores and 95% CI values of studies using the OHIP-49 were converted to match mean and 95% CI of the OHIP-14. After conversion, the mean score on each domain ranges from 0 to 8. If the mean values were not provided in the original paper, median values were used for the data analysis. If the 95% CI values were not given, they were calculated from SD values, stand error (SE) values, IQR values, or first and third quartile range values.
For details, see the methods chapter. 12 For each dental disorder included in the PI dimension (dental anxiety, oral cancer and periodontitis), the pooled mean score was

| Results of search and selection
The initial search identified a total of 2104 studies. 12 After screening of the titles, abstracts and full texts, 23 studies were included in the present review ( Figure 1). 15-37  Table 1.

| Quality assessment
Most patient samples from the studies showed high methodological quality in most categories of the tool (see Figure 2). For representativeness, 4 samples from 2 studies were regarded as having a 'high risk' of bias, 16,21 because the patient populations did not match the target patients of these studies. Four samples from another 2 studies were regarded as having 'unclear risk' of bias, 19,20 because no sufficient information on the source of included patients was provided. For recruitment, 15 samples from 8 studies were regarded as 'high risk' of bias, 15,16,21,22,26,28,30,37 because the patients' recruitment phase was short (< 6 months), the sample size was small (<100 patients) or convenience sampling was used to recruit patients. Six samples from another 4 studies were regarded as 'unclear risk' of bias, 18,20,23,25 because of insufficient information on the type of sampling, period of time of recruitment or sample size. For characterisation, 1 sample from 1 study was regarded as 'high risk' of bias, 20 because the description of the characteristics of clinical settings was insufficient while no samples were regarded as 'unclear risk' of bias. For coverage, 4 samples from 2 studies were regarded as 'high risk' of bias, 28,31 because patients' response rate was too low, while 31 samples from another 14 studies were regarded as 'unclear risk' of bias, 15,17,[19][20][21]23,[25][26][27]29,30,32,35,36 because patients' response rate was not reported and could not be calculated. For standard, 10 samples from 5 studies were regarded as 'high risk' of bias, 16,[19][20][21]25 because the language-version of the OHIP used in the studies was not reported or the language-version of the OHIP used was not validated in previous publications. No samples were regarded as having 'unclear risk' of bias. For reliability, 18 samples from 11 studies were regarded as 'high risk' of bias, 15,16,[19][20][21][22][24][25][26]36 because the used measurement for OHRQoL in these studies was not standardised and the objective of the OHIP was not self-reported by the patients (though with the assistance of others). No samples from the studies were regarded as 'unclear risk' of bias in this category (Figure 2).

| Results of data synthesis and analysis
The mean scores on the PI dimension of the individual samples of patients are presented in Figure 3. It shows that patients with dental anxiety, patients with a gag reflex and patients with oral cancer treated with surgery alone, surgery and radiotherapy, or a combination of surgery, radiotherapy and chemotherapy, had significantly higher mean scores (as based on their 95%CI values) on the PI dimension as compared to the other patients samples. The mean scores for those five patient samples ranged between 4 and 5. The mean scores in the remaining samples of patients ranged between 0 and 3.
The pooled mean score for dental anxiety patient samples (ie 3.2) was the highest, while the pooled mean score for periodontitis patient samples (ie 0.8) was the lowest. The pooled mean score for oral cancer patient samples was 1.9. This suggests that patients with dental anxiety perceive the strongest effect on the PI dimension, while patients with periodontitis perceive the weakest effect on the PI dimension, among these three types of dental disorders.

| D ISCUSS I ON
The aim of the present systematic review was to collect further scientific support for the new four-dimensional structure of OHRQoL by specifically describing the PI dimension in the three dental pa- On 2 categories (recruitment and reliability) a modest quality was observed, while the lowest quality was scored on the category coverage, with a large number of the samples rated as 'unclear'. All in all, this suggests that the included studies were of adequate methodological quality. The present review provides standardised information regarding three dental patient populations that can be used as reference for the PI dimension within the newly proposed OHRQoL four-dimensional structure.
Results showed that the pooled mean scores on the PI domain were relatively low for the sample of periodontitis (0.8) and oral cancer patients (1.9). In comparison, the sample of dentally anxious patients scored significantly higher (3.2). In other words, patients with dental anxiety perceived a stronger impact on the PI dimension of their OHRQoL than those with periodontitis or oral cancer. One explanation for this surprising outcome (especially for the relatively low score of the patients with oral cancer) resembles something TA B L E 1 OHIP scores for included patient samples in the Psychosocial Impact dimension

Year Population
Population, N (% women)

Dental anxiety
Almoznino 2015  in the quality of their social relations since these are valued higher.
Social interactions may also be intensified given the life-threatening condition these patients suffer from. Moreover, having survived cancer can give new meaning to live. Any possible aesthetic impairment as mentioned above can therefore seem relatively less important than before.
Periodontal problems, in the broadest sense of the word, were expected to impact the psychosocial dimension in a different way.
For instance, the PI could be elevated because of possible impaired aesthetics due to missing teeth, or bad breath, perhaps hindering patients in their interaction with others. The results, however, do not support a strong impact on the PI dimension for patients with periodontitis. In fact, the category of periodontal patients, which contained the highest number of patients and samples, shows a consistent result regarding a relatively low mean score on the psychosocial domain.
As illustrated in Figure 3, large heterogeneity was found across the studies included in each of the dental disorder groups. One of the reasons for the large heterogeneity may be that individuals`

Year Population
Population, N (% women)
The 95% CIs of the mean scores for the three dental disorders were not presented. Therefore, even though it was visualised that the patients with dental anxiety had the highest pooled mean score and the patients with periodontitis had the lowest pooled mean score, it was impossible to report whether the difference was sta-

| CON CLUS ION
In summary, within its limitations, the present study provides standardised information about the PI dimension, within the proposed four-dimensional model of OHRQoL, for three dental patient groups (dental anxiety, periodontitis and oral cancer). Results indicate that dental anxiety may have the strongest effect on the PI dimension, while periodontitis may have the weakest effect on the PI dimension among the three dental disorders. Future studies need to confirm whether the reported differences on the PI dimension between the three dental disorders are statistically significant and clinically relevant.

ACK N OWLED G M ENT
We gratefully acknowledged Stella Sekulic, Mike T. John and Nicole Theis-Mahon for their assistance in the electronic literature searching, screening of abstracts and assessment of full-text articles.

CO N FLI C T O F I NTE R E S T
The authors report no conflict of interest.

AUTH O R CO NTR I B UTI O N S
NS contributed to concept, study design, full-text assessment, risk of bias assessment and interpretation of results. AvW and CM contributed to concept, study design, full-text assessment and risk of bias assessment. All authors critically revised the manuscript and provided final approval before submission.

PEER R E V I E W
The peer review history for this article is available at https://publo ns.com/publo n/10.1111/joor.13064.